function sum(num1, num2, num3) {
  return num1 + num2 + num3;
}

console.log("sum.length", sum.length); // sum.length 3

const boundSum0 = sum.bind(null);
console.log("boundSum0.length:", boundSum0.length); // boundSum0.length: 3

const boundSum1 = sum.bind(null, 1);
console.log("boundSum1.length:", boundSum1.length); // boundSum1.length: 2

const boundSum2 = sum.bind(null, 1, 2);
console.log("boundSum2.length:", boundSum2.length); // boundSum2.length: 1

const boundSum3 = sum.bind(null, 1, 2, 3);
console.log("boundSum3.length:", boundSum3.length); // boundSum3.length: 0

const boundSum4 = sum.bind(null, 1, 2, 3, 4);
console.log("boundSum4.length:", boundSum4.length); // boundSum4.length: 0
